Urinary netrin-1 predicts early ischemic acute kidney injury after cardiopulmonary bypass

Abstract

Background Serum creatinine is an unreliable early biomarker for the diagnosis of acute kidney injury (AKI) after cardiac surgery. We need to search for a rapid and dependable marker for the detection of AKI. Aim of work This study was designed to test urinary netrin-1 (Ntn1) as a marker of early kidney injury post cardiac surgery. Our study included 39 patients with preoperative normal creatinine. We measured serum creatinine and urinary Ntn1 at 0, 6, and 24 h after cardiac surgery, AKI was defined according to the KDIGO 2012 definition. Results Fourteen patients developed AKI after cardiac surgery. There was statistically significant elevation in urinary Ntn1 at 6 and 24 h after cardiopulmonary bypass (CPB) surgery in the AKI group, while serum creatinine failed to show any statistically significant elevation at 6 h after CPB in the same group. No statistically significant change was seen in the level of creatinine or urinary Ntn1 at 6 and 24 h after CPB surgery in the non-AKI group. The sensitivity and specificity of urinary Ntn1 to detect AKI at 6 h after CPB surgery was 86.7 and 91.7%, respectively, at a cutoff value of 107.3 pg/ml. Combined urinary Ntn1 and serum creatinine had the same sensitivity and specificity. Conclusion Urinary Ntn1 may be considered as an early sensitive biomarker of AKI at 6 h after cadiopulmonary bypass surgery instead of serum creatinine that rises only 24 h after CPB surgery in patients with cardiac surgery-associated acute kidney injury.

Keywords

• acute kidney injury
• cardiopulmonary bypass
• netrin-1